Systems and Methods for Powering a Load

ABSTRACT

In an example, a light control system includes a power converter, a light source, a sensor, and a control device. The power converter can convert an input power received from a power source to a supply power, and includes a power factor corrector (PFC) configured to adjustably control an electrical parameter of the supply power. The light source can, using the supply power, emit light at an intensity related to the electrical parameter. The sensor can sense a condition related to operation of the light source. The control device is communicatively coupled to the PFC and the sensor, and configured to: (i) receive, from the sensor, a sensor signal indicating an input parameter related to the condition, and (ii) based on sensor signal, provide a feedback signal to the PFC to cause the PFC to adjust, based on the input parameter, the electrical parameter of the supply power.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional PatentApplication No. 62/645,888, filed on Mar. 21, 2018, which is herebyincorporated by reference in its entirety.

FIELD

The present disclosure generally relates to systems and methods forpowering a load, and more particularly to systems and methods fordynamically adjusting a power supplied to the load based on conditionsthat may affect operation of the load. Such loads may include (but arenot constrained to) loads that can benefit from an adjustable powersupply, such as an ultraviolet (UV) light source.

BACKGROUND

Pathogens may be spread between humans, between animals, or betweenhumans and animals in many different ways. Consequently, there is anincreasing need for the disinfection of public environments. Oneapproach for disinfecting an environment involves irradiating theenvironment with ultraviolet (UV) light using a UV light source.

SUMMARY

In an example, a light control system is described. The light controlsystem includes a power converter configured to convert an input powerreceived from a power source to a supply power. The power converterincludes a power factor corrector (PFC) configured to adjustably controlan electrical parameter of the supply power. The light control systemalso includes a light source configured to, using the supply power, emitlight at an intensity related to the electrical parameter of the supplypower. The light control system further includes a sensor configured tosense a condition related to operation of the light source.Additionally, the light control system includes a control devicecommunicatively coupled to the PFC and the sensor. The control device isconfigured to: (i) receive, from the sensor, a sensor signal indicatingan input parameter related to the condition sensed by the sensor, and(ii) based on sensor signal, provide a feedback signal to the PFC tocause the PFC to adjust, based on the input parameter, the electricalparameter of the supply power.

In another example, a light control system includes a power converterand a light source. The power converter includes an input, a powerbuffer, an output, and a PFC. The input is configured to receive aninput power from a power source during a time interval. The power bufferconfigured to store power using the input power received at the inputduring a first portion of the time interval. The output is configured tooutput a supply power during a second portion of the time interval. Thesupply power includes a combination of power from (i) the input powerreceived at the input during the second portion of the time interval and(ii) the power stored in the power buffer during the first portion ofthe time interval. The PFC is between the input and the output. The PFCis configured to adjust an electrical parameter of the supply powerbased on an input parameter.

The light source is configured to, using the supply power during thesecond portion of the time interval, emit light at a target intensity.The input power received during the second portion of the time intervalis insufficient by itself for the light source to emit the light at thetarget intensity.

In another example, a system for supplying power to a load is described.The system includes a power converter, a sensor, and a control device.The power converter is configured to convert an input power receivedfrom a power source to a supply power. The power converter includes oneor more power control modules configured to adjustably control anelectrical parameter of the supply power. The sensor is configured tosense a condition related to operation of the load. The control deviceis communicatively coupled to the one or more power control modules. Thecontrol device is configured to: (i) receive, from the sensor, a sensorsignal indicating an input parameter related to the condition sensed bythe sensor, and (ii) based on sensor signal, provide a feedback signalto the one or more power control modules to cause the one or more powercontrol modules to adjust, based on the input parameter, the electricalparameter of the supply power.

The features, functions, and advantages that have been discussed can beachieved independently in various embodiments or may be combined in yetother embodiments further details of which can be seen with reference tothe following description and drawings.

BRIEF DESCRIPTION OF THE FIGURES

The novel features believed characteristic of the illustrativeembodiments are set forth in the appended claims. The illustrativeembodiments, however, as well as a preferred mode of use, furtherobjectives and descriptions thereof, will best be understood byreference to the following detailed description of an illustrativeembodiment of the present disclosure when read in conjunction with theaccompanying drawings, wherein:

FIG. 1 illustrates a simplified block diagram of a light control systemaccording to an example embodiment.

FIG. 2 illustrates a circuit diagram of a power factor correctoraccording to an example embodiment.

FIG. 3 illustrates a circuit diagram of a power factor correctoraccording to another example embodiment.

FIG. 4 illustrates a circuit diagram of a power factor correctoraccording to another example embodiment.

FIG. 5 illustrates a simplified block diagram of a power bufferaccording to an example embodiment.

FIG. 6 illustrates a simplified block diagram of a system for supplyingpower to a load according to another example embodiment.

FIG. 7 illustrates a simplified block diagram of a system for supplyingpower to a load according to another example embodiment.

FIG. 8 illustrates a simplified block diagram of a system for supplyingpower to a load according to another example embodiment.

FIG. 9 illustrates a flow chart of an example process for operating a UVlight source according to an example embodiment.

FIG. 10 illustrates a flow chart of an example process for operating aUV light source that can be used with the process shown in FIG. 9.

FIG. 11 illustrates a flow chart of an example process for operating aUV light source that can be used with the process shown in FIG. 10.

FIG. 12 illustrates a flow chart of an example process for operating aUV light source that can be used with the process shown in FIGS. 9-11.

FIG. 13 illustrates a flow chart of an example process for operating aUV light source that can be used with the process shown in FIG. 12.

FIG. 14 illustrates a flow chart of an example process for operating aUV light source that can be used with the process shown in FIG. 13.

FIG. 15 illustrates a flow chart of an example process for operating aUV light source that can be used with the process shown in FIGS. 12-14.

DETAILED DESCRIPTION

Disclosed embodiments will now be described more fully hereinafter withreference to the accompanying drawings, in which some, but not all ofthe disclosed embodiments are shown. Indeed, several differentembodiments may be described and should not be construed as limited tothe embodiments set forth herein. Rather, these embodiments aredescribed so that this disclosure will be thorough and complete and willfully convey the scope of the disclosure to those skilled in the art.

The systems and methods of the present disclosure provide power supplycontrol systems for supplying a dynamically adjustable level of power toa load to, for instance, operate the load at a target level ofoperational output over time and/or over a series of activation cyclesof the load. As described in further detail below, in some examples, theload may experience degraded operational output due to, for instance,changes in the load and/or changed conditions in an environment in whichthe load operates. The systems and methods of the present disclosure cansense such changes and provide feedback to one or more components of apower supply control system to dynamically adjust an electricalparameter of a supply power provided to the load. In this way, thesystems and methods of the present application can compensate forchanges in the load and/or the environment over time and/or the seriesof activation cycles.

In some examples, the systems and methods of the present disclosureprovide light control systems and methods for operating a UV lightsource to achieve a target level of antimicrobial efficacy over a seriesof activation cycles. When activated during an activation cycle, the UVlight source emits UV light, which can kill and/or disablemicroorganisms such as bacteria, viruses, molds, and/or other pathogens.For example, when microorganisms are exposed to a sufficiently high doseof UV light, the UV light can damage nucleic acids and/or disrupt thedeoxyribonucleic acid (DNA) of the microorganisms, rendering themicroorganisms unable to carry out cellular functions and infect people.

The antimicrobial efficacy of the UV light during the activation cycleis related to factors such as, for instance, the length of time amicroorganism is exposed to the UV light (i.e., the “exposure time”),the intensity of the UV light, and the wavelength of the UV light. Asone example, the antimicrobial efficacy of the UV light at a particularwavelength can be specified as a UV dose, which can be determined basedon an equation having the general form of:

UV dose=UV light intensity x exposure time  (eq. 1)

where the UV dose is specified in mWs/cm², the UV light intensity isspecified in mW/cm² at a predetermined distance (e.g., one meter) fromthe UV light source, and the exposure time is specified in seconds.

Over time, the intensity of the UV light emitted by the UV light sourcedeclines due to, for example, lamp lumen depreciation (LLD) and/or lampdirt depreciation (LDD). For instance, LLD can be caused by chemicalreactions, which can deposit light-absorbing particles within the UVlight source, over multiple activation cycles. Whereas, LDD can becaused by an accumulation of debris (e.g., dirt and/or dust particles)on an exterior surface of the UV light source, which block UV lightemission.

Additionally, for example, the intensity of the UV light emitted by theUV light source can be affected by the temperature of the UV lightsource. For instance, the temperature of the UV light source can varydue to changes in an ambient temperature of an environment in which theUV light source is operating, and/or due to heat resulting fromoperation of the UV light source itself. Accordingly, because theintensity of the UV light source changes over multiple activationcycles, it can be challenging to maintain the target level ofantimicrobial efficacy throughout the life of the UV light source. Otherenvironmental factors may also affect operation of the UV light sourceover the life of the UV light source.

The example systems and methods described herein can beneficiallyovercome challenges to operating a UV light source at a target level ofantimicrobial efficacy over multiple activation cycles and/or the lifeof the UV light source. In particular, the systems and methods candynamically adjust an electrical parameter of a supply power provided tothe UV light source to compensate for changes in the intensity of the UVlight and/or other operating conditions over a series of activationcycles.

Within examples, a light control system can include a power converter, alight source, one or more sensors, and a control device. The powerconverter can provide a supply power to the light source, which thelight source can use to emit light during a series of activation cycles.The sensor(s) can sense a condition related to operation of the lightsource, and provide to the control device a sensor signal indicting aninput parameter related to the condition sensed by the sensor(s). Thecontrol device can provide a feedback signal to the power converter tocause the power converter to adjust, based on the input parameter, anelectrical parameter of the supply power.

Also, within examples, the power converter can include a plurality ofmodules that are operable to convert an input power received from apower source to the supply power having the electrical parameter. Insome examples, the control device can provide the feedback signal to oneor more of the modules to selectively those module(s) to adjust theelectrical parameter of the power supply responsive to changes in theoperating conditions that may affect operation of the light source.Additionally, as described in further detail below, the control devicecan be separate from the sensor(s) and/or integrated with the sensors inexample embodiments. As such, the sensor(s) can sense the operatingconditions and responsively communicate, directly and/or indirectly,with the modules of the power converter to adjust the electricalparameter of the supply power.

Also, within examples, the systems and methods of the presentapplication can provide for operating the UV light source (or anotherload) in a limited-power environment. Because the UV light sourceconverts electrical power into the UV light, the UV light source mayrequire at least a threshold amount of power to emit the UV light at theintensity and/or for the exposure time providing the target level ofantimicrobial efficacy. The threshold amount of power required to emitthe UV light at the target level of antimicrobial efficacy may be basedon characteristics of the UV light source such as, for example, a typeof UV light source, and/or a size of the UV light source.

In a limited-power environment, a power source and/or an electricaldistribution system may provide a power that is insufficient by itselffor activating the UV light source to emit the UV light at the targetlevel of antimicrobial efficacy (e.g., at a target intensity of the UVlight). In one example, the UV light source can be coupled to a powersource, which is configured to generate a power that is less than thethreshold amount of power required by the UV light source to emit the UVlight at the target level of antimicrobial efficacy. For instance, theUV light source can be installed in an environment in which it isdesirable to reduce (or minimize) the size and/or weight of the powersource.

In another example, the power source may be configured to generate asufficient amount of power, but an electrical distribution system maysupply portions of the generated power to other systems as well suchthat only an insufficient portion of the power is available to the UVlight source. For instance, a vehicle can have an electricaldistribution system that provides specific portions of a power suppliedby a power source to various subsystems of the vehicle in accordancewith a power budget. In this way, each subsystem receives an amount ofpower that is sufficient to meet its needs. A problem is presented,however, when the vehicle is to be retrofitted with the UV light sourceas the power requirements of the UV light source may not have been takeninto consideration when the power budget and electrical distributionsystem were designed.

As noted above, the systems and methods described herein can alsobeneficially overcome challenges to operating the UV light source at thetarget level of antimicrobial efficacy in a limited-power environment(e.g., a vehicle and/or an aircraft lavatory). For instance, withinexamples, a light control system can receive an input power from a powersource during a time interval. A UV light source of the light controlsystem is deactivated during a first portion of the time interval, andthe UV light source is activated to emit UV light during a secondportion of the time interval. However, the input power received duringthe second portion of the time interval is insufficient by itself foractivating the UV light source to emit the UV light at the target levelof antimicrobial efficacy.

To address this limitation of the input power, the light control systemcan store the input power in a power buffer during the first portion ofthe time interval. Later, during the second portion of the timeinterval, the light control system can provide to the UV light source asupply power that combines (i) the input power received during thesecond portion of the time interval and (ii) the power stored in thepower buffer during the first portion of the time interval. Thecombination of power is sufficient for activating the UV light source toemit the UV light at the target level of antimicrobial efficacy.

Within examples, the light control system described herein can belocated in any environment having a power supply, which can benefit fromdisinfection. For instance, the light control system can be in a vehicle(e.g., an aircraft, a boat, a train, an automobile, an unmanned vehicle,a transportation vehicle with both ground and non-ground capabilities,an unmanned vehicle, and/or an air-cargo vehicle), a medical environment(e.g., a hospital, a doctor office, and/or other healthcare facility), arestaurant, an office, and/or a household. In one implementation, thelight control system can be located in a lavatory of a vehicle (e.g., anairplane).

Referring now to FIG. 1, a light control system 100 is depictedaccording to an example embodiment. As shown in FIG. 1, the lightcontrol system 100 includes a UV light source 110. When activated, theUV light source 110 can emit UV light 112 to provide a target level ofantimicrobial efficacy. For instance, the UV light source 110 can emitthe UV light 112 at a predetermined wavelength and intensity for apredetermined exposure time to achieve the target level of antimicrobialefficacy during an activation cycle. In one example, the UV light source110 can emit the UV light 112 at an intensity of 10 mW/cm² for anexposure time of 10 seconds to achieve the target level of antimicrobialefficacy for the activation cycle.

Also, as examples, the UV light source 110 can include one or moreexcimer bulbs, mercury-vapor lamps, downshifting phosphor lamps, excimerlasers, organic light emitting diodes (OLEDs), and/or light emittingdiodes (LEDs). More generally, the UV light source 110 can be a lightsource that emits the UV light 112 at a wavelength within the UVspectrum (i.e., between approximately 10 nanometers (nm) andapproximately 400 nm). In some implementations, the UV light source 110can be a light source that emits UV light 112 at a wavelength within thefar-UV spectrum (e.g., between approximately 190 nm and approximately240 nm). For instance, in one implementation, the UV light source 110can be a light source that emits the UV light 112 at a wavelength ofapproximately 222 nm. By emitting the UV light 112 at a wavelength inthe far-UV spectrum, the UV light source 110 can more rapidly disinfectthe environment than by emitting the UV light 112 at other wavelengthsin the UV spectrum.

As shown in FIG. 1, the light control system 100 also includes a powerconverter 114 coupled to the UV light source 110. The power converter114 receives an input power from a power source 116 at an input 118 andoutputs a supply power to the UV light 112 source at an output 120. Asan example, the power source 116 can provide the input power as analternating-current (AC) power. In one implementation, the power source116 can provide the input power as a three-phase AC power with a voltageof 115 volts (V) and a frequency of 400 Hertz (Hz). For instance, in avehicle, the power source 116 can include an engine turbine thatgenerates electrical energy and an electrical distribution system thatprovides the generated electrical energy to the light control system 100in the form of the input power. Other example power sources 116 are alsopossible.

The power converter 114 converts the input power into the supply power.Within examples, the supply power can have a different AC waveform thanthe input power. For instance, the supply power can have a differentfrequency, voltage, and/or current than the input power. More generally,the supply power can have a wattage that is greater than a wattage ofthe input power. As such, the power converter 114 can provide the UVlight source 110 with the supply power, which is sufficient to emit theUV light 112 at the target level of antimicrobial efficacy. In oneexample, the input power can have a wattage that is less than 1 kW andthe supply power can have a wattage that is equal to or greater than 1kW.

In FIG. 1, the power converter 114 includes the input 118, a rectifier122, a direct current (DC) link 124, an inverter 126, a power buffer128, and the output 120. The rectifier 122 is coupled to and receivesthe input power from the input 118. The rectifier 122 can convert the ACinput power into a DC power. In an example, the rectifier 122 includes apower factor corrector (PFC) 130 that corrects a power factor of theinput power to facilitate more efficient use of the input power by thelight control system 100. The PFC 130 can also facilitate isolating thelight control system 100 from the power source 116 (and/or otherelectrical subsystems coupled to the power source 116). Within examples,the PFC 130 can include a passive PFC circuit, an active PFC circuit,and/or a dynamic PFC circuit.

The rectifier 122 is coupled to the inverter 126 via the DC link 124. Asdescribed in further detail below, when the UV light source 110 isactivated, the inverter 126 converts the DC power received from therectifier 122 into an AC power, which provides a portion of the supplypower at the output 120. The DC link 124 facilitates the coupling of therectifier 122 and the inverter 126. In one example, the DC link 124 caninclude a capacitor coupled in parallel between the rectifier 122 andthe inverter 126. The DC link 124 can assist in mitigating transientspropagating toward the power source 116 and/or assist in smoothingpulses in the rectified DC power provided by the rectifier 122.

As shown in FIG. 1, the power buffer 128 is coupled in parallel betweenthe rectifier 122 and the DC link 124, and between the DC link 124 andthe inverter 126. The power buffer 128 stores power using the inputpower received at the input 118 when the UV light source 110deactivated. As examples, the power buffer 128 can include a battery, acapacitor, and/or another type of energy storage device.

In the example of FIG. 1, the power buffer 128 includes a plurality ofDC-to-DC converters 132 coupled to each other. When the UV light source110 is deactivated, the DC-to-DC converters 132 receive the DC powerfrom the rectifier 122. In one implementation, the DC-to-DC converters132 include a first DC-to-DC converter that steps down the DC powerreceived from the rectifier 122 and a second DC-to-DC converter thatsteps up the DC power. This configuration of the DC-to-DC converters 132can beneficially reduce (or minimize) the size and/or weight of thepower buffer 128.

As noted above, inverter 126 is coupled to the rectifier 122 and thepower buffer 128. In this arrangement, when the UV light source 110 isactivated, the inverter 126 can receive the DC power from the rectifier122 and the power stored in the power buffer 128. The inverter 126 canconvert this combination of DC power from the rectifier 122 and thepower buffer 128 into the supply power, which has an AC waveform. In anexample, the inverter 126 can include a pulse-width modulator (PWM) 134,which can switch on and off to control a frequency of the supply power.In another example, the inverter 126 can additionally or alternativelyinclude a sine wave generator and/or a carrier wave generator to convertthe combination of DC power to the supply power.

As further shown in FIG. 1, the light control system 100 can alsoinclude a control device 136 communicatively coupled to the powerconverter 114, a light sensor 138, and one or more trigger sensors 140.In general, the control device 136 can (i) communicate with the lightsensor 138 and/or the trigger sensor(s) 140 to receive informationrelated to the operation of the light control system 100 and/or (ii)communicate with the power converter 114 to control operation of thelight control system 100 based on the information received from thelight sensor 138 and/or the trigger sensor(s) 140. As described infurther detail below, the control device 136 can additionally oralternatively be incorporated in the light sensor 138, the triggersensor(s) 140, and/or other components of the light control system 100.

In some examples, the control device 136 can control the operation ofthe light control system 100 by activating the UV light source 110. Forinstance, in one example, the trigger sensor(s) 140 can detect one ormore trigger conditions and responsively generate a trigger-sensorsignal indicating that the trigger condition(s) were detected. Thecontrol device 136 can (i) receive the trigger-sensor signal indicatingthat the trigger condition was detected, (ii) determine, based on thetrigger-sensor signal, that one or more criteria are met, and (iii)responsive to the determination that the one or more criteria are met,transmit a control signal to activate the UV light source 110.

As examples, the trigger sensor(s) 140 can include a motion sensor, anoccupancy sensor, a thermal sensor, a door open/close sensor, aninfrared sensor device, an ultrasonic sensor device, a floor pressuresensor, and/or other types of sensors. For instance, in an example inwhich the light control system 100 is located on a vehicle having alavatory, the trigger condition(s) detected by the trigger sensor(s) 140can include a door of the lavatory being opened, the door of thelavatory being closed, the lavatory being occupied, and/or the lavatorybeing unoccupied. Additionally, for example, the one or more criteriathat is used by the control device 136 to determine whether to activatethe UV light source 110 can include one or more criterion such as a doorof the lavatory being closed, the lavatory being unoccupied, thelavatory having been occupied a predetermined number of times since aprevious activation of the UV light source 110, and/or a predeterminedamount of time having passed since the previous activation of the UVlight source 110.

In an additional or alternative example, the trigger sensor(s) 140 canbe configured to sense a parameter related to the operation of one ormore component of the power converter 114. For instance, the triggersensor(s) 140 can include a sensor for measuring the amount of powerstored in the power buffer 128. In such example, the trigger sensor(s)140 can generate the trigger-sensor signal to indicate the amount ofpower is stored in the power buffer 128, and the control device 136 candetermine whether the indicated amount of power is sufficient toactivate the UV light source 110 at the target level of antimicrobialefficacy during an activation cycle. For instance, the control device136 can compare the amount of power indicated by the trigger-sensorsignal to a threshold amount of power stored in the control device 136.Responsive to the control device 136 determining that the indicatedamount of power is greater than the threshold amount of power, thecontrol device 136 can transmit the control signal to the powerconverter 114 to activate the UV light source 110. Whereas, responsiveto the control device 136 determining that the indicated amount of poweris less than the threshold amount of power, the control device 136 cancontinue to wait until the power buffer 128 has stored at least thethreshold amount of power before transmitting the control signal.

In an additional or alternative example, the trigger sensor(s) 140 caninclude a user input device that is actuatable by an operator. Asexamples, the user input device can include one or more buttons, mice,keypads, keyboards, and/or switches. Responsive to the operatoractuating the user input device, the user input device can transmit thetrigger-sensor signal to the control device 136 to cause the controldevice 136 to transmit the control signal to the power converter 114 foractivating the UV light source 110. In this way, the trigger sensor(s)140 can provide for on-demand actuation of the light control system 100to disinfect a given environment (e.g., a hospital room and/or anaircraft lavatory).

In some examples, the control device 136 can additionally oralternatively control the operation of the light control system 100 bydeactivating the UV light source 110. For instance, the control device136 can deactivate the UV light source 110 to prevent (or delay) afuture activation cycle and/or to terminate a current activation cycle(i.e., to override a decision, based on a trigger-sensor signal, toactivate the UV light source 110).

Within examples, the control device 136 can deactivate the UV lightsource 110 responsive to an occurrence of one or more overrideconditions to enhance (or maximize) operational safety and/or reduce (orminimize) operational transients. In general, the override conditionscan include, for example, conditions relating to one or more componentsof the light control system 100 (e.g., a temperature of a component ofthe light control system 100 and/or an amount of energy stored in thepower buffer 128) and/or conditions relating to an environment in whichthe component(s) of the light control system 100 are located (e.g., atemperature of the environment and/or an occupancy of the environment).As further examples, the override conditions can additionally oralternatively include conditions relating to (i) an occurrence of anemergency state of one or more devices external to the light controlsystem 100 (e.g., an emergency state of one or more devices on anaircraft and/or in a hospital), and/or (ii) an occurrence of an attemptto tamper with one or more components of the light control system 100.

In one implementation, the trigger sensor(s) 140 can detect the overridecondition(s) and responsively generate an override-sensor signalindicating that the override condition(s) were detected. The controldevice 136 can (i) receive the override-sensor signal indicating thatthe override condition(s) were detected, (ii) determine, based on theoverride-sensor signal, that one or more criteria are met, and (iii)responsive to the determination that the one or more criteria are met,transmit a control signal to deactivate the UV light source 110.

In one example, the trigger sensor(s) 140 can detect when a door opensor a person enters a vicinity of the light control system 100, and thecontrol device 136 can responsively cause the light control system 100to deactivate as a security and/or safety feature. Additionally, forinstance, when the door subsequently closes and/or the personsubsequently leaves the vicinity of the light control system 100, thetrigger sensor 140 can transmit the trigger-sensor signal to the controldevice 136 to activate the light control system 100 and/or prepare thelight control system 100 to be activated responsive to a nexttrigger-sensor signal from the trigger sensor(s) 140.

In another example, the trigger sensor(s) 140 can detect when atemperature of the UV light source 110 and/or an environment in whichthe UV light source 110 is located is greater than a thresholdtemperature level. The threshold temperature level can be related to,for instance, an overheating condition and/or an out-of-tolerancetemperature condition. Responsive to the trigger sensor(s) 140 detectingthat the temperature is greater than the threshold temperature level,the control device 136 can deactivate the light control system 100 toreduce (or minimize) a risk of an operational transient in the lightcontrol system 100. Additionally, when the trigger sensor(s) 140 detectthat the temperature of the UV light source 110 and/or the environmentreturns to an in-tolerance temperature (e.g., a temperature less thanthe threshold temperature level), the trigger sensor(s) 140 can transmitthe trigger-sensor signal to the control device 136 to activate thelight control system 100 and/or prepare the light control system 100 tobe activated responsive to a next trigger-sensor signal from the triggersensor(s) 140.

In some examples, the control device 136 can transmit the control signalto the power converter 114 to deactivate the UV light source 110. Forinstance, in one implementation, the control device 136 can transmit thecontrol signal to one or more switches 142A-142C to actuate theswitch(es) 142A-142C from a closed state to an open state to deactivatethe component(s) of the light control system 100 downstream of theswitch(es) 142A-142C. In the closed state, each switch 142A-142C canconduct power through the switch 142A-142C. Whereas, in the open state,each switch 142A-142C can inhibit or prevent power transmission throughthe switch 142A-142C (e.g., actuate the switches 142A-142C to preventthe UV light source 110 from receiving the supply power).

In FIG. 1, for instance, the switches 142A-142C include a first switch142A located at any point between the input 118 and the rectifier 122, asecond switch 142B located at any point between the rectifier 122 andthe power buffer 128, and a third switch 142C located at any pointbetween the inverter 126 and the UV light source 110 (e.g., the output120). In this arrangement, the control device 136 can selectivelytransmit the control signal to one or more of the switches 142A-142C tospecifically deactivate the components of the light control system 100downstream of those switches 142A-142C. This can allow the controldevice 136 to selectively deactivate different portions of the lightcontrol system 100 based on the specific override condition detected.

For instance, as one example, in a situation in which an overridecondition occurs with respect to the UV light source 110, it can bebeneficial to allow the power buffer 128 to continue to store power(e.g., charge up) while the override condition is resolved for the UVlight source 110. This can beneficially allow for more rapid activationof the UV light source 110 using the power stored in the power buffer128 when the override condition is resolved. In FIG. 1, the controldevice 136 can transmit the control signal to the third switch 142C toactuate the third switch 142C to the open state while the first switch142A and the second switch 142B remain in the closed state. As such, thepower buffer 128 can continue to receive power from the rectifier 122while the output 120 and the UV light source 110 are disconnected fromthe inverter 126 (and, thus, deactivated).

As another example, in a situation in which the trigger sensor(s) 140detect an occurrence of an override condition with respect to the powerbuffer 128 (e.g., an out-of-tolerance temperature condition), thecontrol device 136 can deactivate the power buffer 128 (e.g., bytransmitting the control signal to the actuate the second switch 142B tothe open state) while allowing power to continue to be supplied to othercomponents of the light control system 100 (e.g., by maintaining thefirst switch 142A and the third switch 142C in the closed state). Inpractice, for instance, the trigger sensor(s) 140 can detect when atemperature of the power buffer 128 and/or an environment in which thepower buffer 128 is located is greater than a threshold temperaturelevel (e.g., indicating an occurrence of an out-of-tolerance temperaturecondition and/or an overheating condition). Responsive to the triggersensor(s) 140 detecting that the temperature is greater than thethreshold temperature level, the control device 136 can deactivate thepower buffer 128 to reduce (or minimize) a risk of an operationaltransient in the light control system 100. Additionally, when thetrigger sensor(s) 140 detect that the temperature of the power buffer128 and/or the environment returns to an in-tolerance temperature (e.g.,a temperature less than the threshold temperature level), the triggersensor(s) 140 can transmit the trigger-sensor signal to the controldevice 136 to activate the power buffer 128 and resume storing power inthe power buffer 128.

Although three switches 142A-142C are depicted in FIG. 1, the lightcontrol system 100 can include a lesser quantity and/or a greaterquantity of switches 142A-142C at additional or alternative locationswithin the light control system 100 in other example embodiments. Forinstance, in another example, the switch(es) 142A-142C can beadditionally or alternatively provided in the rectifier 122, in theinverter 126, in the power buffer 128, at a point before the input 118,at a point after the output 120, and/or any other point between thepower source 116 and the output 120. This can beneficially allow forgreater options of deactivating the select components of the lightcontrol system 100. Specifically, the trigger sensor(s) 140 and thecontrol device 136 can operate in a similar manner to that describedabove to selectively deactivate the rectifier 122, the PFC 130, theinverter 126, and/or the PWM 134 responsive to detecting an occurrenceof an override condition in connection with the component(s) to bedeactivated.

In some examples, the combination of the trigger sensor(s) 140 and thecontrol device 136 can additionally or alternatively operate together tomonitor the amount of power stored in the power buffer 128, anddetermine that the amount of power stored in the power buffer 128 isgreater than a threshold amount of power. Responsive to the controldevice 136 determining that the amount of power stored in the powerbuffer 128 is greater than the threshold amount of power, the controldevice 136 can deactivate the power buffer 128 to inhibit supplyingadditional power to the power buffer 128. Later, when the control device136 determines that the amount of power stored in the power buffer 128is less than the threshold amount of power, the control device 136 cantransmit another control signal to activate the power buffer 128. Thiscan facilitate discontinuing supplying power to the power buffer 128after the power buffer 128 is fully charged, and then recharging thepower buffer 128 after an activation cycle is completed. Additionally oralternatively, deactivating and activating the power buffer 128 canfacilitate stopping and/or slowing down a rate of power storage toreduce the likelihood (or avoid) overpowering the UV light source 110(e.g., providing more power than is needed by the UV light source 110).

In the examples described above, the light control system 100 canoperate to selectively activate and/or deactivate one or more componentsof the light control system 100. As noted above, the light controlsystem 100 can additionally or alternatively operate in connection withthe power converter 114, the light sensor 138, and/or the triggersensor(s) 140 to dynamically adjust an electrical parameter of thesupply power provided by the power converter 114 to the UV light source110. Specifically, the light sensor 138 and/or the trigger sensor(s) 140can sense one or more operating conditions that can relate to operationof the UV light source 110 (and/or affect an output of the UV lightsource 110). For example, as noted above, the operating condition(s)that can affect the intensity of the UV light 112 emitted by the UVlight source 110 include, for instance, LLD and/or LDD. As additionalexamples, the operating condition(s) can relate to a temperature of theUV light source 110, an operating frequency of the UV light source 110,a remaining life expectancy of the UV light source 110, a powerefficiency of the UV light source 110, an irradiance of the UV light 112emitted by the UV light source 110, a voltage level of the UV lightsource 110, an efficacy level of the UV light source 110, and/or an ageof the UV light source 110 (e.g., a remaining life expectancy of the UVlight source 110).

As described in detail below, responsive to the light sensor 138 and/orthe trigger sensor(s) 140 sensing the operating condition(s), the lightsensor 138 and/or the trigger sensor(s) 140 can transmit to the controldevice 136 a sensor signal indicating an input parameter related to theoperating condition sensed by the light sensor 138 and/or the triggersensor(s) 140. Based on the sensor signal, the control device 136 canprovide a feedback signal to the PFC 130, the PWM 134, and/or the powerbuffer 128 to cause the PFC 130, the PWM 134, and/or the power buffer128 to adjust the electrical parameter of the supply power (e.g., thefrequency, the pulse width, the wattage, and/or the voltage of the ACwaveform of the supply power) based on the input parameter. In this way,the light control system 100 can maintain a target level ofantimicrobial efficacy over a series of activation cycles and/orotherwise adjust operation of the UV light source 110 based on theoperating condition(s).

In some implementations, the control device 136 can provide the feedbacksignal to the PWM 134 to adjust, based on the input parameter, a pulsewidth and/or a frequency of the supply power. In other implementations,the control device 136 can additionally or alternatively provide thefeedback signal to the PFC 130 to adjust, based on the input parameter,a voltage and/or wattage of the supply power. In other implementations,the control device 136 can additionally or alternatively provide thefeedback signal to the power buffer 128 to adjust, based on the inputparameter, the voltage and/or the wattage of the supply power. Thus,within examples, the control device 136 can cause any one or acombination of the PFC 130, the PWM 134, and/or the power buffer 128 toadjust the electrical parameter of the supply power based on the inputparameter related to the operating conditions sensed by the light sensor138 and/or the trigger sensor(s) 140.

In some examples, the light sensor 138 can sense the UV light 112emitted by the UV light source 110, measure an optical parameter of thesensed UV light 112, and provide a sensor signal to the control device136 indicating the optical parameter measured by the light sensor 138.Accordingly, the light sensor 138 can be positioned such that a portionof the UV light 112 emitted by the UV light source 110 is incident onthe light sensor 138. As examples, the light sensor 138 can include oneor more photodiodes, photojunction devices, light dependent resistors(LDRs), and/or photoconductive cells to sense and measure the opticalparameter of the UV light 112.

In these examples, the optical parameter measured by the light sensor138 can be the input parameter indicated by the sensor signal. Thecontrol device 136 can receive the sensor signal from the light sensor138, and compare the optical parameter indicated by the sensor signal toa target optical parameter. The target optical parameter can be a fixedvalue and/or an adjustable value. Based on the comparison, the controldevice 136 can provide a feedback signal to the power converter 114 tocause the power converter 114 to adjust an electrical parameter of thesupply power.

In an example in which the electrical parameter is the frequency and/orthe pulse width of the AC waveform of the supply power, the feedbacksignal can cause the PWM 134 to switch of and off based on the feedbacksignal to adjust the frequency and/or the pulse-width of the AC waveformof the supply power. In one implementation, the optical parametermeasured by the light sensor 138 can be related to a resonance of thepower converter 114 relative to the UV light source 110. For instance,when the UV light source 110 is activated using the supply power, a gasin the UV light source 110 can undergo a process of ion formation andion recombination, which can define a frequency of the UV light source110. When the AC waveform of the supply power has a frequency and/orpulse width that is resonant with the frequency of the UV light source110, the intensity of the UV light 112 emitted by the UV light source110 is at a maximum intensity consistent with the input power receivedat the input 118.

Within examples, the light sensor 138 can measure the irradiance of theUV light 112 as an indication of the resonance of the power converter114 relative to the UV light source 110. For instance, based on one ormore characteristics of the power converter 114 and/or the UV lightsource 110, the irradiance of the UV light 112 can be expected to have atarget irradiance when the power converter 114 is in resonance with theUV light source 110 (i.e., when the frequency and/or pulse width of thesupply power is in resonance with the frequency of the UV light source110). The control device 136 can thus compare the irradiance indicatedby the sensor signal to the target irradiance and, based on thecomparison, the control device 136 can provide the feedback signal tothe power converter 114 to tune the power converter 114 to the frequencyof the UV light source 110. Because the frequency of the UV light source110 may drift over time, the control device 136 and the light sensor 138can dynamically adjust operation of the power converter 114 to maintainthe power converter 114 in resonance with the UV light source 110 over aplurality of activation cycles of the UV light source 110 (e.g., overthe life of the UV light source 110).

Further, by tuning the power converter 114 to the frequency of the UVlight source 110, the efficiency of the UV light source 110 can beincreased (or maximized). In turn, this can allow for the power buffer128 to be relatively smaller and/or lighter as less power may need to bestored in the power buffer 128 to meet the power requirements of the UVlight source 110 for emitting the UV light 112 at the target level ofantimicrobial efficacy.

As noted above, the target optical parameter can be a fixed value in oneexample. In an alternative example, the target optical parameter can beadjustable. For instance, the control device 136 can iteratively adjustthe target optical parameter using one or more previously measuredoptical parameters to maintain the measured irradiance at a peak value.

In one implementation in which the PWM 134 adjusts the electricalparameter, the PFC 130 can provide a fixed DC power to the inverter 126.FIG. 2 depicts a PFC 230 according to one example embodiment in whichthe PFC 230 provides a fixed DC power to the inverter 126. As shown inFIG. 2, the PFC 230 includes a PFC circuit 244 having a first PFC input246, a second PFC input 248, and a PFC output 250. The first PFC input246 is configured to receive, via the input 118, the input power fromthe power source 116. The second PFC input 248 is configured receive asignal from a feedback circuit 252. The PFC output 250 is configured tooutput a DC power, which is based on the input power at the first PFCinput 246 and the signal at the second PFC input 248. As such, the PFCoutput 250 can be coupled to the power buffer 128 and/or the inverter126 in FIG. 1.

The feedback circuit 252 is coupled to the PFC output 250 and the secondPFC input 248. In this arrangement, the signal that the feedback circuit252 provides to the second PFC input 248 is based on the DC power at thePFC output 250. As such, the feedback circuit 252 can sense variationsin the DC power at the PFC output 250 and provide the signal to thesecond PFC input 248 that indicate the sensed variations. The PFCcircuit 244 can thus use the signal at the second PFC input 248 as abasis for converting the input power to the DC power with a fixedvoltage (i.e., correcting the power factor and/or regulating the voltageof the DC power at the PFC output 250).

In FIG. 2, the feedback circuit 252 includes a signal conditioningcircuit 254, an operational amplifier (op-amp) 256, and a referencevoltage source 258. The signal conditioning circuit 254 is coupled tothe PFC output 250 and an inverting input 256A of the op-amp 256, thereference voltage source 258 is coupled to a non-inverting input 256B ofthe op-amp 256, and an output 256C of the op-amp 256 is coupled to thesecond PFC input 248. In this arrangement, the op-amp 256 is configuredto output to the second PFC input 248 the signal, which is based on adifference between a voltage provided by the signal conditioning circuit254 at the inverting input 256A and a voltage of the reference voltagesource 258 at the non-inverting input 256B. As the voltage of thereference voltage source 258 is a fixed value, the feedback circuit 252is configured to cause the PFC circuit 244 to maintain the DC power atthe PFC output 250 at a single, fixed voltage.

In the examples described above, the electrical parameter of the supplypower that is adjusted is the frequency and/or the pulse width of the ACwaveform of the supply power. As noted above, however, the electricalparameter of the supply power that is adjusted can additionally oralternatively be a voltage and/or a wattage of the supply power in otherexamples. In such examples, the control device 136 can provide thefeedback signal to the PFC 130 and/or the power buffer 128 to adjust thevoltage and/or the wattage of the supply power.

FIG. 3 depicts a PFC 330 that can adjust, based on the feedback signal,the voltage of the DC power provided to the inverter 126 and/or thepower buffer 128 in FIG. 1, according to an example embodiment. In FIG.3, the PFC 330 is a modified version of the PFC 230 depicted in FIG. 2,wherein the reference voltage source 258 that causes the PFC 230 toprovide a single, fixed voltage at the PFC output 250 in FIG. 2 has beenreplaced by components that facilitate dynamically selecting a referencevoltage from among a plurality of reference voltages and, thus,adjusting the voltage of the DC power provided to the inverter 126and/or the power buffer 128. For instance, as described below, the PFC330 can include an operational amplifier (op-amp) having a variableinput as a reference voltage.

As shown in FIG. 3, the PFC 330 includes a PFC circuit 344 having afirst PFC input 346, a second PFC input 348, and a PFC output 350. Thefirst PFC input 346 is configured to receive, via the input 118, theinput power from the power source 116. The second PFC input 348 isconfigured receive a signal from a feedback circuit 352. The PFC output350 is configured to output a DC power, which is based on the inputpower at the first PFC input 346 and the signal at the second PFC input348. As such, the PFC output 350 can be coupled to the power buffer 128and/or the inverter 126 in FIG. 1.

The feedback circuit 352 is coupled to the PFC output 350 and the secondPFC input 348. In this arrangement, the signal that the feedback circuit352 provides to the second PFC input 348 is based on the DC power at thePFC output 350. As such, the feedback circuit 352 can sense variationsin the DC power at the PFC output 350 and provide the signal to thesecond PFC input 348 based, in part, on the sensed variations. This canallow the PFC circuit 334 to use the signal at the second PFC input 348as a basis for converting the input power at the first PFC input 346 toa regulated, power-factor corrected DC power at the PFC output 350.

Additionally, the feedback circuit 352 is configured to provide thesignal at the second PFC input 348 based on the input parameter relatedto the operating condition(s) that are sensible by the light sensor 138and/or the trigger sensor(s) 140. As the input parameter can vary withchanges in the operating condition(s), the signal at the second PFCinput 348 can also allow the PFC circuit 344 to dynamically adjust thevoltage level of the DC power at the PFC output 350 responsive to thechanges in the operating condition(s). Stated differently, the PFC 330can dynamically adjust the voltage of the DC power by outputting aregulated, power-factor corrected voltage level selected from among aplurality of regulated, power-factor corrected voltage levels based onthe input parameter.

As noted above, the signal at the second PFC input 348 is based, inpart, on the input parameter related to the operating condition(s)sensed by the light sensor 138 and/or the trigger sensor(s) 140. Thiscan be achieved based on the control device 136 communicatively coupledto the PFC 130 as shown in FIG. 1. For instance, the control device 136can (i) receive, from the light sensor 138 and/or the trigger sensor(s)140, the sensor signal indicating the input parameter related to theoperating condition sensed by the light sensor 138 and/or the triggersensor(s) 140, and (ii) based on sensor signal, provide the feedbacksignal to the PFC 330 to cause the PFC 330 to adjust, based on the inputparameter, the electrical parameter of the supply power.

Specifically, in FIG. 3, the feedback circuit 352 can include a logiccircuit 360, which receives the feedback signal from the control device136. The logic circuit 360 is configured to select a reference voltagefrom among a plurality of reference voltages based on the inputparameter. For instance, in one implementation, the logic circuit 360can include a variable voltage divider having an output voltage, whichis dynamically adjustable based on the input parameter. In FIG. 3, thelogic circuit 360 is depicted as being configured to select among threereference voltages based on the input parameter. However, in otherexamples, the logic circuit 360 can be configured to select among Ndifferent reference voltages based on the input parameter, where N is aninteger value that is greater than one.

As shown in FIG. 3, the feedback circuit 352 includes a first op-amp356, a second op-amp 362, and the logic circuit 360. The first op-ampincludes a first inverting input 356A, a first non-inverting input 356B,and a first output 356C. The first output 356C of the first op-amp 356is coupled to the second PFC input 348. The first inverting input 356Aof the first op-amp 356 is coupled to the PFC output 350 by a signalconditioning circuit 354. The second op-amp 362 includes a secondinverting input 362A, a second non-inverting input 362B, and a secondoutput 362C. The second output 362C of the second op-amp 362 is coupledto the first non-inverting input 356B of the first op-amp 356. Thesecond inverting input 362A of the second op-amp 362 is coupled to aground 364. The logic circuit 360 is coupled to the second invertinginput 362A of the second op-amp 362. The logic circuit 360 is thusconfigured to provide the adjustable reference voltage to the secondinverting input 362A of the second op-amp 362.

In this arrangement, the logic circuit 360 can receive the feedbacksignal from the control device 136 and select, based on the inputparameter, the reference voltage from among the plurality of referencevoltages. The logic circuit 360 can provide the selected referencevoltage to the second inverting input 362A of the second op-amp 362. Thesecond op-amp 362 then outputs, from the second output 362C to the firstnon-inverting input 356B of the first op-amp 356, a signal based on adifference between the selected reference voltage at the secondinverting input 362A and the ground 364 at the second non-invertinginput 362B. The first op-amp 356 then outputs, from the first output356C to the second PFC input 348, a signal based on a difference betweenthe signal received from the second op-amp and a signal received fromthe signal conditioning circuit 354 (which is based on the DC power atthe PFC output 350).

The signal provided by the feedback circuit 352 at the second PFC input348 is thus based on the feedback signal received by the PFC 330 fromthe control device 136 and the input parameter sensed by the lightsensor 138 and/or the trigger sensor(s) 140. Accordingly, because the DCpower at the PFC output 350 is based on the input power at the first PFCinput 346 and the signal at the second PFC input 348, the PFC 330 candynamically adjust the voltage of the DC power to be at a regulated,power-corrected level (which is selected from among a plurality ofregulated, power-factor corrected voltage levels) based on the inputparameter. In this way, the PFC 330 is configured to adjustably controlthe electrical parameter of the supply power.

As noted above, the operating condition(s) can relate to a temperatureof the light source, an operating frequency of the light source, aremaining life expectancy of the light source, a power efficiency of thelight source, an irradiance of light emitted by the light source, avoltage level of the light source 110, an efficacy level of the lightsource 110, and/or an age of the light source 110. Thus, when one ormore of these operating condition(s) change over time and/or a series ofactivation cycles, the light sensor 138 and/or the trigger sensor(s) 140can sense the changes and the control device 136 can responsively causethe PFC 130 to adjust the voltage of the DC power provided to theinverter 126 and thereby adjust the voltage of the supply power providedto the UV light source 110. This can, for example, facilitate the UVlight source 110 emitting the UV light 112 at a target intensity thatprovides a target level of antimicrobial efficacy over time and/or theseries of activation cycles. Additionally, for example, adjusting thevoltage of the supply power based on changed operating condition(s) canfacilitate extending the useful life of the UV light source 110.

Referring now to FIG. 4, a PFC 430 that can adjust, based on thefeedback signal, the voltage of the supply power is illustratedaccording to another example embodiment. As shown in FIG. 4, the PFC 430includes a PFC circuit 444 having a first PFC input 446, a second PFCinput 448, and a PFC output 450. The first PFC input 446 is configuredto receive, via the input 118, the input power from the power source116. The second PFC input 448 is configured receive a signal from afeedback circuit 452. The PFC output 450 is configured to output the DCpower, which is based on the input power at the first PFC input 446 andthe signal at the second PFC input 448. The feedback circuit 452 iscoupled to the PFC output 450 and the second PFC input 448.

Like the feedback circuit 352 in FIG. 3, the feedback circuit 452 isconfigured to receive the feedback signal from the control device 136and provide the signal to the second PFC input 448 to dynamically adjustthe voltage of the DC power to be at a regulated, power-corrected level(which is selected from among a plurality of regulated, power-factorcorrected voltage levels) based on the input parameter. However, thefeedback circuit 452 shown in FIG. 4 differs in some ways from thefeedback circuit 352 shown in FIG. 3.

As shown in FIG. 3, the feedback circuit 352 includes a first op-amp356, a second op-amp 362, and the logic circuit 360. The first op-ampincludes a first inverting input 356A, a first non-inverting input 356B,and a first output 356C. The first output 356C of the first op-amp 356is coupled to the second PFC input 348. The first inverting input 356Aof the first op-amp 356 is coupled to the PFC output 350 by a signalconditioning circuit 354. The second op-amp 362 includes a secondinverting input 362A, a second non-inverting input 362B, and a secondoutput 362C. The second output 362C of the second op-amp 362 is coupledto the first non-inverting input 356B of the first op-amp 356. Thesecond inverting input 362A of the second op-amp 362 is coupled to aground 364. The logic circuit 360 is coupled to the second invertinginput 362A of the second op-amp 362. The logic circuit 360 is thusconfigured to provide the adjustable reference voltage to the secondinverting input 362A of the second op-amp 362.

As shown in FIG. 4, the feedback circuit 452 includes a first op-amp456, a second op-amp 462, and a logic circuit 460. The first op-amp 456includes a first inverting input 456A, a first non-inverting input 456B,and a first output 456C. The first output 456C of the first op-amp 456is coupled to the second PFC input 448, and the first inverting input456A of the first op-amp 456 is coupled to the PFC output 450 by asignal conditioning circuit 454. The second op-amp 462 includes a secondinverting input 462A, a second non-inverting input 462B, and a secondoutput 462C. The second output 462C of the second op-amp 462 is coupled,via the signal conditioning circuit 454, to the PFC output 450 and thefirst inverting input 456A of the first op-amp 456. The secondnon-inverting input 462B of the second op-amp 462 is coupled to a ground464.

Additionally, as shown in FIG. 4, the feedback circuit 452 includes areference voltage source 466 coupled to the first non-inverting input456B of the first op-amp 456 and the second non-inverting input 462B ofthe second op-amp 462. The reference voltage source 466 is configured toprovide a fixed voltage to the first non-inverting input 456B and thesecond non-inverting input 462B. The feedback circuit 452 also includesa logic circuit 460 coupled to the second inverting input 462A of thesecond op-amp 462. The logic circuit 460 is configured to provide anadjustable reference voltage to the second inverting input 462A of thesecond op-amp 462. As described above with respect to the logic circuit360 shown in FIG. 3, the logic circuit 460 is configured to select thereference voltage from among a plurality of reference voltages based onthe input parameter.

In this arrangement, the logic circuit 460 can receive the feedbacksignal from the control device 136 and select, based on the inputparameter, the reference voltage from among the plurality of referencevoltages. The logic circuit 460 can provide the selected referencevoltage to the second inverting input 462A of the second op-amp 462. Thesecond op-amp 462 then outputs, from the second output 462C to thesignal conditioning circuit 454, a signal based on a difference betweenthe selected reference voltage at the second inverting input 462A andthe ground 464 at the second non-inverting input 462B.

The signal conditioning circuit 454 can provide a signal to the firstinverting input 456A of the first op-amp 456 that is based on (i) the DCpower at the PFC output 450 and (ii) the signal provided by the secondoutput 462C of the second op-amp 462. Additionally, the referencevoltage source 466 can provide the fixed voltage to the firstnon-inverting input 456B of the first op-amp 456. The first op-amp 456then outputs, from the first output 456C to the second PFC input 448, asignal based on a difference between the fixed voltage from thereference voltage source 466 and the signal received from the signalconditioning circuit 454 (which is based on the DC power at the PFCoutput 450 and the reference voltage selected based on the inputparameter).

In this way, the signal provided by the feedback circuit 452 at thesecond PFC input 448 is based on the feedback signal received by the PFC430 from the control device 136 and the input parameter sensed by thelight sensor 138 and/or the trigger sensor(s) 140. Accordingly, becausethe DC power at the PFC output 450 is based on the input power at thefirst PFC input 446 and the signal at the second PFC input 448, the PFC430 can dynamically adjust the voltage of the DC power to be at aregulated, power-corrected level (which is selected from among aplurality of regulated, power-factor corrected voltage levels) based onthe input parameter.

In some examples, changing the voltage at the PFC 130 can providegreater flexibility in certain parameters than used by the PWM 134(e.g., parameters of the PWM 134 such as, for instance, voltage andcurrent de-rating of the components in the PWM 134, thermal dissipationof PWM 134 as compared to parameters of the PFC 130 such as, forinstance, voltage, interact with frequency and pulse width).

As noted above, the control device 136 can additionally or alternativelyprovide the feedback signal to the power buffer 128 to adjust thevoltage and/or the wattage of the supply power. FIG. 5 depicts asimplified block diagram of the power buffer 128 according to an exampleembodiment. As shown in FIG. 5, the power buffer 128 can include aninput 568 configured to receive an electrical power from the PFC 130during a first portion of a time interval. The power buffer 128 can alsoinclude an energy storage device 570 configured to store the electricalpower received at the input 568 during the first portion of the timeinterval. The power buffer 128 can further include an output 572configured to be coupled to the PWM 134. The output 572 is configuredto, during a second portion of the time interval, output the electricalpower stored in the energy storage device 570 during the first portionof the time interval.

Also, as shown in FIG. 5, the power buffer 128 includes the DC-to-DCconverters 132 that can step down and/or step up the power received atthe input 568 and/or the power provided at the output 572. Additionally,the power buffer 128 includes a control terminal 574 configured toreceive, from the control device 136, the feedback signal forcontrolling operation of the energy storage device 570. For instance, inone implementation, the feedback signal can cause the DC-to-DCconverters 132 to step up and/or step down power stored in the energystorage device 570 and/or drawn from the energy storage device 570 basedon the input parameter. In this way, the control device 136 canadditionally or alternatively provide the feedback signal to the powerbuffer 128 to adjust, based on the input parameter sensed by the lightsensor 138 and/or the trigger sensor(s) 140, the voltage and/or thewattage of the supply power.

As noted above, the light sensor 138 and/or the trigger sensor(s) 140can sense the operating condition(s) and provide a sensor signalindicating an input parameter related to the operating condition(s)sensed by the light sensor 138 and/or the trigger sensor(s) 140.Additionally, as noted above, the operating condition(s) and the inputparameter(s) can relate to a temperature of the UV light source 110, anoperating frequency of the UV light source 110, a remaining lifeexpectancy of the UV light source 110, a power efficiency of the UVlight source 110, an irradiance of the UV light 112 emitted by the UVlight source 110, a voltage level of the UV light source 110, anefficacy level of the UV light source 110, and/or an age of the UV lightsource. The operating condition(s) and the input parameter(s) canadditionally or alternatively relate to an occupancy of an environmentin which the UV light source 110 is located by humans and/or babies,and/or a vicinity of the humans and/or babies to the UV light source110. The operating condition(s) and the input parameter(s) canadditionally or alternatively relate to a level of power that has beenstored in the power buffer 128 and/or an occurrence of a maximum levelof power being stored in the power buffer 128.

In some examples, the trigger sensor(s) 140 can sense a temperature ofthe UV light source 110 and responsively adjust, based on the sensedtemperature, the electrical parameter of the supply power. Additionaldetails regarding using the temperature to adjust and/or determine thesupply power provided to the UV light source 110 are described in U.S.patent application Ser. No. 15/810,414, filed Nov. 13, 2017, which ishereby incorporated by reference in its entirety.

For example, as described in U.S. patent application Ser. No.15/810,414, the UV light source 110 can overheat due to operatingconditions occurring internal to the UV light source 110 and/or externalto the UV light source 110. For instance, during operation of the UVlight source 110, filaments and/or columns of conducting plasma of gascan form between dielectrics and electrodes. The filaments can attach ata set location within the UV light source 110 and form voltagedischarges, which heat a metal mesh and may form holes and/or cracks inthe metal mesh. In this manner, the voltage discharges reduce a lifespanof the UV light source 110.

Within examples, the trigger sensor(s) 140 can include at least onetemperature sensor that is configured to monitor the internaltemperature of the UV light source 110. Thus, when the filaments createone or more hot spots, which cause temperature spikes along a metal meshof the UV light source 110, the temperature sensor can measure the hotspots. In some implementations, the temperature spikes may reach atemperature over approximately 100 degrees Celsius, which can affect themetal mesh and/or the UV light source 110. Based on the temperaturesensed by the trigger sensor(s) 140, the control device 136 can causethe PFC 130, the PWM 134, and/or the power buffer 128 to adjust theelectrical parameter of the supply power and thereby reduce electricalpower supplied to the UV light source 110. The adjustment or reductionof the electrical power shifts the filament with respect to thedielectrics within the UV light source 110. The shift of the filamentadjusts a position of the hot spot, thereby extending the lifespan ofthe UV light source 110.

In another example, the trigger sensor(s) 140 can monitor a temperatureexternal to the UV light source 110 (e.g., in an environment in whichthe UV light source 110 is located). In one implementation, to maintaina desired functioning of the UV light source 110, the temperature of theload surrounding measured at a certain distance and/or within certaintime intervals can be maintained within a predetermined range oftemperature values. The trigger sensor(s) 140 can thus indicate themeasured temperature to the control device 136, and the control device136 can compare the measured temperature to the predetermined range oftemperature values. If the control device 136 determines that thetemperature sensed by the trigger sensor(s) 140 is outside of thepredetermined range of temperature values, the control device 136 candetermine that the UV light source 110 is underperforming. Additionally,the control device 136 can cause the PFC 130, the PWM 134, and/or thepower buffer 128 to adjust the electrical parameter of the supply powerand thereby reduce electrical power supplied to the UV light source 110to increase the wattage of the supply power provided to the UV lightsource 110.

In general, the control device 136 is a computing device that isconfigured to control operation of the light control system 100 (and, asdescribed below, a power converter 614 shown in FIG. 6). As such, thecontrol device 136 can be implemented using hardware, software, and/orfirmware. For example, the control device 136 can include one or moreprocessors and a non-transitory computer readable medium (e.g., volatileand/or non-volatile memory) that stores machine language instructions orother executable instructions. The instructions, when executed by theone or more processors, cause the light control system 100 to carry outthe various operations described herein. The control device 136, thus,can receive data (including data indicated by the sensor signals,trigger-sensor signals, and/or override signals) and store the data inmemory as well.

Within examples, the control device 136 can be integrated with one ormore of the components of the light control system 100. For instance,aspects of the control device 136 described herein can be incorporatedin and/or performed by the control device 136 can be integrated with thePFC 130, the PWM 134, the power buffer 128, the UV light source 110, thelight sensor 138, and/or the trigger sensor(s) 140. Accordingly,principles and advantages of distributed processing, such as redundancy,replication, and the like, also can be implemented, as desired, toincrease the robustness and performance of the devices and systems ofthe control device 136.

For instance, in one example, the control device 136 can be the PFC 130.In another example, the control device 136 can be the PWM 134. Inanother example, the control device 136 can be the power buffer 128. Inanother example, the control device 136 can be the UV light source 110.In another example, the control device 136 can be the light sensor 138.In another example, the control device 136 can be the trigger sensor(s)140. As described above, in another example, the control device 136 canbe a combination of two or more of the PFC 130, the PWM 134, the powerbuffer 128, the UV light source 110, the light sensor 138, and thetrigger sensor(s) 140. In yet another example, the control device 136can be a distinct device that is separate from the PFC 130, the PWM 134,the power buffer 128, the UV light source 110, the light sensor 138, andthe trigger sensor(s) 140. Accordingly, within examples, the PFC 130,the PWM 134, the power buffer 128, the UV light source 110, the lightsensor 138, and/or the trigger sensor(s) 140 can perform some or all ofthe functions and operations described above for the control device 136.

Additionally, for example, although FIG. 1 depicts the components of thelight control system 100 as indirectly communicating with each other viathe control device 136, the components of the light control system 100can directly communicate with each other in implementations in which thecontrol device 136 is integrated in the components of the light controlsystem 100. For instance, aspects of the control device 136 can beintegrated in the light sensor 138 and/or the trigger sensor(s) 140 suchthat the light sensor 138 and/or the trigger sensor(s) 140 can directlycommunicate the feedback signal and input parameter to the PFC 130, thePWM 134, and/or the power buffer 128. Also, for instance, aspects of thecontrol device 136 can be integrated in the light sensor 138 and/or thetrigger sensor(s) 140 such that the light sensor 138 and/or the triggersensor(s) 140 can activate and/or deactivate components of the lightcontrol system 100, as described above. Similarly, within examples, thelight sensor 138 and/or the trigger sensor 140 can be integrated withother components of the light control system 100 such as, for instance,the UV light source 110 and/or the power buffer 128.

In the examples described above, the light control system 100 includesthe power buffer 128. The power buffer 128 can be beneficial inlimited-power environments, including aircraft and non-aircraftimplementations of the light control system 100. However, in otherexamples, the light control system 100 can omit the power buffer 128(e.g., in implementations in which a relatively high voltage is readilyavailable).

In some implementations (such as, e.g., an airplane), the light controlsystem 100 can provide for transmission of a three-phase power. Whereas,in other implementations (e.g., a commercial application such as ahospital), the light control system 100 can provide for transmission asingle phase power.

In operation, the light control system 100 receives, at the input 118 ofthe power converter 114, the input power from the power source 116during a first portion of a time interval and a second portion of thetime interval. The UV light source 110 is deactivated during the firstportion of the time interval. The UV light source 110 is activatedduring the second portion of the time interval. However, the input powerreceived during the second portion of the time interval is insufficientby itself for the UV light source 110 to emit the UV light 112 at theintensity and/or for the exposure time providing the target level ofantimicrobial efficacy.

While the UV light source 110 is deactivated during the first portion ofthe time interval, the rectifier 122 converts the input power to the DCpower and the DC power is stored in the power buffer 128. After thefirst portion of the time interval, the control device 136 can activatethe UV light source 110 during the second portion of the time interval.For example, the control device 136 can activate the UV light source 110responsive to the trigger sensor(s) 140 detecting the triggercondition(s) and the control device 136 determining, based at least inpart on the trigger-sensor signal received from the trigger sensor(s)140, that the criteria for activating the UV light source 110 are met.

During the second portion of the time interval, the power converter 114outputs the supply power from the output 120 to the UV light source 110.The UV light source 110 can use the supply power during the secondportion of the time interval to emit the UV light 112 at the intensityand/or for the exposure time providing the target level of antimicrobialefficacy.

As noted above, the supply power can include a combination of power from(i) the input power received at the input 118 during the second portionof the time interval, and (ii) the power stored in the power buffer 128during the first portion of the time interval. For instance, when the UVlight source 110 is activated during the second portion of the timeinterval, the rectifier 122 can convert the input power to the DC powerand provide the DC power to the inverter 126. Additionally, when the UVlight source 110 is activated during the second portion of the timeinterval, the power buffer 128 can sense a voltage droop andresponsively provide the power stored in the power buffer 128 to theinverter 126. The inverter 126 thus receives the DC power from therectifier 122 and the stored power from the power buffer 128, andconverts this combination of power into the supply power. By combiningthe input power received at the input 118 during the second portion ofthe time interval and the power stored in the power buffer 128, thepower converter 114 can provide the UV light source 110 with a powerthat is sufficient to activate the UV light source 110 at the targetlevel of antimicrobial efficacy.

In one example, the target level of antimicrobial efficacy can bedefined by an intensity of 10 mW/cm² intensity and an exposure time of10 seconds. In this example, the input 118 can receives the input poweras a three-phase AC power with a voltage of approximately 115 V_(AC), afrequency of approximately 400 Hz, and a current of 0.5 Amps (A) suchthat the input power has a wattage of approximately 100 W (i.e., lessthan 1 kW). As such, the input power is insufficient by itself toactivate the UV light source 110 at the target level of antimicrobialefficacy. The rectifier 122 can convert the input power to the DC powerhaving a voltage of approximately 200 V_(DC) and a current ofapproximately 0.5 A. The power buffer 128 can include a first DC-to-DCconverter that steps down the DC power from 200 V_(DC) to 28 V_(DC), anda second DC-to-DC converter that steps the DC power from 28 V_(DC) to200 V_(DC).

In this arrangement, during the first portion of the time interval, therectifier 122 converts the input power to the 200 V_(DC) power and thepower buffer 128 stores the 200 V_(DC) power. During the second portionof the time interval, the rectifier 122 converts the input power to the200 V_(DC) power and provides the 200 V_(DC) power to the inverter 126.Also, during the second portion of the time interval, the power buffer128 provides the stored power to the inverter 126 with a voltage ofapproximately 200 V_(DC) and a current of approximately 5 A. As aresult, the inverter 126 receives the combination of power at 200 V_(DC)and a current of at least 5 A such that the supply power has a wattageequal to or greater than 1 kW. In this example, the power buffer 128 canhave an energy storage capacity at least large enough to provide thestored power at 200 V_(DC) and 5 A for the 10 second exposure time. Inthis way, the power converter 114 can provide the UV light source 110with sufficient power to achieve the target level of antimicrobialefficacy during the activation cycle of the UV light source 110.

In the example described above, the target level of antimicrobialefficacy is UV dose of approximately 10 mWs/cm². In additional oralternative examples, the target level of antimicrobial efficacy can bea UV dose between approximately 2 mWs/cm² and approximately 500 mWs/cm².Different microorganisms may have different abilities to withstandexposure to the UV light 112. In some implementations, the target levelof antimicrobial efficacy can be based on a target microorganism-killrate for one or more types of microorganisms that are targeted fordisinfection by the light control system 100. As examples, the targetedmicroorganism-kill rate can be approximately 80%, approximately 90%,approximately 95%, approximately 99%, approximately 99.9%, and/orapproximately 99.99% of the one or more target organisms irradiated bythe UV dose.

Additionally, in the example described above, the power stored in thepower buffer 128 provides approximately 90% of the supply power and theinput power received during the second portion of the time intervalprovides approximately 10% of the supply power. In additional oralternative examples, the input power received during the second portionof time can provide approximately 5% to approximately 95% of the supplypower and the power stored in the power buffer 128 can provide theremainder of the supply power.

Additionally, during the time interval, the light sensor 138 and/or thetrigger sensor(s) 140 can sense an operating condition related to theoperation of the UV light source 110, and provide to the control device136 a sensor signal indicating an input parameter related to theoperating condition. Based on sensor signal, the control device 136 canprovide the feedback signal to the power converter 114 to cause thepower converter 114 to adjust, based on the input parameter, theelectrical parameter of the supply power.

Additionally or alternatively, during the time interval, the lightsensor 138 and/or the trigger sensor(s) 140 can sense an overridecondition, and the control device 136 can responsively provide anoverride signal to one or more switches 142A-142C to deactivate one morecomponents of the light control system 100.

In the examples described above with respect to FIGS. 1-5, the powerconverter 114 is a part of a light control system 100 for powering a UVlight source 110. However, as noted above, aspects of the light controlsystem 100 can be applied to dynamically adjust a supply power providedto other types of loads. FIGS. 6-8 depict simplified block diagrams ofexample systems for powering a load according to additional oralternative example embodiments. Within examples, the systems describedwith respect to FIGS. 6-8 can perform any or all of the functions and/oroperations described above with respect to FIGS. 1-5 (e.g., dynamicallyadjusting a supply power provided to the load, triggering activation oroperation of the load, and/or overriding a decision to activate oroperate the load).

FIG. 6 depicts a system 600 according to an example embodiment. As shownin FIG. 6, the system 600 includes a power source 616, a power converter614, a load 610, and a power control system 676. The power source 616 iscoupled to and configured to provide an input power to the powerconverter 614. The power converter 614 is communicatively coupled to thepower control system 676. In general, the power control system 676 isconfigured to provide a plurality of control signals to the powerconverter 614 to control operations performed by the power converter 614for converting the input power into a supply power. The power converter614 is coupled to the load 610, and configured to provide the supplypower to the load 610. The load 610 can use the supply power to performoperations. In the examples described above, the load 610 can be a UVlight source 110. However, in other examples, the load 610 canadditionally or alternatively be a non-UV light source (e.g., a laser),a motor, a travelling wave tube (TWT), a radar device, an electronicthruster (e.g., a thruster that accelerates ions at relativisticvelocities to provide thrust), a laser inferometer gauge, a light sourcethat uses a constant non-varying output to emit light, and/or a devicethat uses a constant non-varying output to generate heat.

More generally, the load 610 can be any load that can benefit from arelatively precise voltage and/or current feed. For instance, in animplementation in which the load 610 includes an electronic thruster,the efficiency of the electronic thruster (and, thus, an ability to keepa satellite in a particular orbit over a useful life of the satellite)can be based, at least in part, on accurate control of the voltagesupplied to the electronic thruster over time. Additionally, forinstance, in an implementation in which the load 610 includes a laserinferometer gauge, the laser inferometer gauge can be used (e.g., on anairplane) to determine a shim thickness for mating body sections. Insuch an implementation, relatively precise voltages may beneficiallyprovide for relatively high accuracy of the laser inferometer gauge andassist in dynamically adjusting the power provided to the laserinferometer gauge to help compensate for aging of system components.

The power converter 614 converts the input power into the supply power.Within examples, the supply power can have a different AC waveform thanthe input power. For instance, the supply power can have a differentfrequency, voltage, and/or current than the input power. As shown inFIG. 6, the power converter 614 can include an input 618, one or morepower control modules 630, 628, 634, and an output 620. The powerconverter 614 receives an input power from a power source 616 at theinput 618 and outputs the supply power to the load 612 source at theoutput 620.

In general, the power control modules 630, 628, 634 can operate, basedon control signals from the power control system 676, to adjust one ormore electrical parameters of the power transmitted through the powerconverter 614. For instance, in FIG. 6, the power control modules 630,628, 634 include a first power control module 630, a second powercontrol module 628, and a third power control module 634. The firstpower control module 630 can receive the input power from the input 618and output a first adjustable power to the second power control module628 and/or the third power control module 634. The second power controlmodule 628 can receive the first adjustable power from the first powercontrol module 630 and output a second adjustable power to the thirdpower control module 634. The third power control module 634 can receivethe first adjustable power from the first power control module 630 andthe second adjustable power from the second power control module 628,and output a third adjustable power to the output 620.

In this example, the supply power provided to the load 610 is the thirdadjustable power; however, in other examples that may omit the thirdpower control module 634, the supply power can include the firstadjustable power, the second adjustable power, or a combination of thefirst adjustable power and the second adjustable power.

Also, as shown in FIG. 6, a first feedback module 652 can receive anindication of the first adjustable power outputted by the first powercontrol module 630 and provide to the first power control module 630 asignal that is based on (i) the indication of the first adjustable powerand (ii) a first control signal received from the control device 636.For instance, the first power control module 630 and the first feedbackmodule 652 can form a PFC such as, for instance, the PFCs 330, 430 thatincluded a feedback circuit 352, 452. As examples, the second powercontrol module 628 can include a power buffer (e.g., the power buffer128), and the third power control module 634 can include a PWM (e.g.,the PWM 134). However, in other examples, any one or a combination ofthe power control modules 630, 628, 634 can include a PFC, a PWM, and/ora power buffer.

The power control system 676 can include a control device 636, and oneor more sensors 678. The sensor(s) 678 can include, for instance, one ormore trigger sensors 640 (e.g., the trigger sensors 140) and/or one ormore light sensors 138 (or, more generally, load sensors 680 thatdirectly measure an operational output of the load 610). As such, thesensor(s) 678 can sense a condition (e.g., a trigger condition, anoverride condition, and/or an operating condition) relating to the loadand/or an environment in which the load is located. Additionally, thesensor(s) 678 can provide a signal to the control device 636 to indicatea parameter relating to the sensed condition. The control device 636 canreceive the signal from the sensor(s) 678 and determine, based on theparameter, whether to trigger the system 600, deactivate the system 600,and/or adjust an electrical parameter of the first adjustable power, thesecond adjustable power, and/or the third adjustable power. Forinstance, as described above, the control device 636 can perform acomparison of the parameter and one or more threshold values, anddetermine whether to perform the above actions based on the comparison.Additionally or alternatively, the control device 636 can automaticallymake a determination to perform some or all of the actions responsive tothe control device 636 receiving a signal from the sensor(s) 678.

Although the control device 636 is depicted as a part of the powercontrol system 676, the control device 636 can additionally oralternatively be integrated with the first power control module 630, thesecond power control module 628, the third power control module 634, thetrigger sensor(s) 640, the load sensor(s) 680, and/or the load 610 inexample embodiments (i.e., as described above with respect to thecontrol device 136 in FIGS. 1-5). Thus, as described above, thecomponents of the system 600 can directly and/or indirectly communicatewith each other within examples.

Responsive to control device 636 determining that an action is to betaken based on the signal from the sensor(s) 678, the control device 636can provide further signals to the power converter to trigger the system600, deactivate the system 600, and/or adjust an electrical parameter ofthe first adjustable power, the second adjustable power, and/or thethird adjustable power. For example, the control device 636 can providethe first control signal to the first feedback module 652 to adjust theelectrical parameter of the first adjustable power outputted by thefirst power control module 630. For instance, the first feedback module652 can include a logic circuit (e.g., the logic circuit 360 or thelogic circuit 460), which receives the first control signal and selectsa reference voltage from among a plurality of reference voltages basedon the first control signal, as described above. The first feedbackmodule 652 can also include a plurality of op-amps as described abovewith respect to FIGS. 3-4.

Additionally, for example, the control device 636 can provide a secondcontrol signal to the second power control module 628. Based on thesecond control signal, the second power control module 628 can adjustthe electrical parameter of the second adjustable power. Similarly, forexample, the control device 636 can provide a third control signal tothe third power control module 634. Based on the third control signal,the third power control module 634 can adjust the electrical parameterof the third adjustable power.

In this arrangement, the power control system 676 can selectivelytransmit the first control signal, the second control signal, and/or thethird control signal at the same time or at different times duringoperation of the system 600 to achieve one or more adjustments to thesupply power provided to the load 610. This can beneficially allow forrelatively greater control over the supply power and/or allow for finelytuned adjustments to the operation of the load 610 based on theconditions sensed by the sensor(s) 678.

For instance, at a first time, the control device 636 can transmit thefirst control signal to the first feedback module 652 to adjust theelectrical parameter of the first adjustable power. At a second time,the control device 636 can transmit the second control signal to thesecond power control module 628 to adjust the electrical parameter ofthe second adjustable power. At a third time, the control device 636 cantransmit the third control signal to the third power control module 634to adjust the electrical parameter of the third adjustable power. At afourth time, the control device 636 can transmit the first controlsignal to the first feedback module 652 to adjust the electricalparameter of the first adjustable power and transmit the second controlsignal to the second power control module 628 to adjust the electricalparameter of the second adjustable power. At a fifth time, the controldevice 636 can transmit the second control signal to the second powercontrol module 628 to adjust the electrical parameter of the secondadjustable power and transmit the third control signal to the thirdpower control module 634 to adjust the electrical parameter of the thirdadjustable power. At a sixth time, the control device 636 can transmitthe first control signal to the first feedback module 652 to adjust theelectrical parameter of the first adjustable power, transmit the secondcontrol signal to the second power control module 628 to adjust theelectrical parameter of the second adjustable power, and transmit thethird control signal to the third power control module 634 to adjust theelectrical parameter of the third adjustable power.

As noted above, the power converter 614 can include one or more of thefirst power control module 630, the second power control module 628, andthe third power control module 634. Accordingly, in some examples, thepower converter 614 can include the first power control module 630 andthe first feedback module 652, and omit the second power control module628 and/or the third power control module 634. In other examples, thepower converter 614 can include the second power control module 628 andomit the first power control module 630 (and the first feedback module652) and/or the third power control module 634. In other examples, thepower converter 614 can include the third power control module 634 andomit the first power control module 630 (and the first feedback module652) and/or the second power control module 628.

Also, in other examples, the power converter 614 can include a feedbackmodule communicatively coupled to the third power control module 634 ina manner similar to the coupling of the first power control module 630and the first feedback module 652, and the feedback control modulecoupled to the third power control module 634 can receive the controlsignal from the control device 636. In such examples, the feedbackmodule can receive an indication of the third adjustable power outputtedby the third power control module 634 and provide to the third powercontrol module 634 a signal that is based on (i) the indication of thethird adjustable power and (ii) the control signal received from thecontrol device 636.

FIG. 7 depicts a system 700 according to another example embodiment. Asshown in FIG. 7, the system 700 is substantially similar to the system600 shown in FIG. 6, except the system 700 omits the second powercontrol module 628 and the third power control module 634. In thisexample, the first power control module 630 provides the firstadjustable power as the supply power to the output 620.

Additionally, as shown in FIG. 7, the first power control module 630 caninclude a first input 782 configured to receive the input power from thepower source 616, a second input 784 configured to receive the signalfrom the first feedback module 652, and an output 786 configured tooutput the supply power, which is based on the input power at the firstinput 782 and the signal at the second input 784. As noted above, thefirst feedback module 652 is coupled to the output 786 and the secondinput 784, and the first feedback module 652 is configured to providethe signal at the second input 784 based on the input parameter relatedto the condition that is sensible by a sensor(s) 678. Also, as notedabove, the condition that is sensed by the sensor(s) 678 can be relatedto the operation of the load 610.

In one example, the first power control module 630 can include a PFCcoupled to the first input 782, the second input 784, and the output786. In another example, the first power control module 630 canadditionally or alternatively include a power buffer coupled to thefirst input 782, the second input 784, and the output 786. In anotherexample, the first power control module 630 can additionally oralternatively include a PWM coupled to the first input 782, the secondinput 784, and the output 786. Also, in some examples, the first powercontrol module 630 can be integrated with the first feedback module 652.

FIG. 8 depicts a system 800 according to another example embodiment. Asshown in FIG. 8, the system 800 is substantially similar to the system600 shown in FIG. 6, except the system 800 omits the third power controlmodule 634. Additionally, in FIG. 8, the power converter 614 furtherincludes an optional second feedback module 852 coupled to the output ofthe second power control module 628 and in communication with thecontrol device 636. In this arrangement, the second feedback module 852can receive an indication of the second adjustable power outputted bythe second power control module 628 and provide to the second powercontrol module 6228 a signal that is based on (i) the indication of thesecond adjustable power and (ii) the second control signal received fromthe control device 636.

In general, the feedback control module(s) can provide the systems ofthe present disclosure with accurate and precise control of theelectrical parameter(s) to assist the power control module(s) (e.g., thePFC 130, the PWM 134, and/or the power buffer 128) in providing anoutput that meets power specifications for operating the load 610 at adesired quality and/or performance level over the life of the load 610(and also improving the life expectancy of the load 610). For example,the feedback control module(s) can help the power buffer 128 to increasethe accuracy and precision of a power buffering capability whileproviding for safe and secure operation of the system. Additionally, forexample, the feedback control module(s) can help the first power controlmodule (such as, e.g., the PFC 130) improve the accuracy and precisionof the DC output, which can help to provide an accurate power suppliedto the load 610 and, thus, facilitate relatively consistent functioningof the load 610 along with a longer life expectancy. Also, the feedbackcontrol module(s) can help the second power control module (such as,e.g., the PWM 134) to improve the accuracy and precision of the powersupplied to the load 610, which can help to provide a relativelyconsistent functioning of the load 610 along with a longer lifeexpectancy.

Referring now to FIG. 9, a flowchart for a process 900 of operating a UVlight source is illustrated according to an example embodiment. As shownin FIG. 9, at block 910, the process 900 includes receiving, at an inputof a power converter, an input power from a power source during a firstportion of a time interval and a second portion of the time interval. Atblock 912, during the first portion of the time interval, the process900 includes using the input power to store power in a power buffer. Atblock 914, during the second portion of the time interval, the process900 includes outputting a supply power from an output of the powerconverter. The supply power includes a combination of power from (i) theinput power received at the input during the second portion of the timeinterval and (ii) the power stored in the power buffer during the firstportion of the time interval. At block 916, the process 900 includesactivating, using the supply power during the second portion of the timeinterval, the UV light source to emit UV light at an intensity providinga target level of antimicrobial efficacy. For the process 900, the inputpower received during the second portion of the time interval isinsufficient by itself for activating the UV light source to emit the UVlight at the intensity providing the target level of antimicrobialefficacy.

FIGS. 10-15 depict additional aspects of the process according tofurther examples. As shown in FIG. 10, the process 900 can furtherinclude sensing the UV light emitted by the UV light source to measurean optical parameter of the UV light at block 918. In an example, theoptical parameter can be related to a resonance of a power converterrelative to the UV light source. At block 920, the process 900 caninclude providing, based on the measured optical parameter, feedback totune the power converter to a frequency of the UV light source.

As shown in FIG. 11, sensing the UV light to measure the opticalparameter at block 918 can include measuring an irradiance of the UVlight at block 922. As shown in FIG. 12, the process 900 can include,prior to storing the power in the power buffer, converting the inputpower from an AC power to a DC power at block 924. As shown in FIG. 13,storing the power in the power buffer at block 912 can include storingthe DC power in a plurality of DC-to-DC converters coupled to each otherat block 926. As shown in FIG. 14, storing the DC power in the pluralityof DC-to-DC converters at block 926 can include stepping down the DCpower in a first DC-to-DC converter and stepping up the DC power in asecond DC-to-DC converter at block 928. As shown in FIG. 15, convertingthe input power at block 924 can include correcting a power factor ofthe input power at block 930.

The process 900 can be a linear and/or a non-linear process. Any of theblocks shown in FIGS. 9-14 may represent a module, a segment, or aportion of program code, which includes one or more instructionsexecutable by a processor for implementing specific logical functions orsteps in the process. The program code may be stored on any type ofcomputer readable medium or data storage, for example, such as a storagedevice including a disk or hard drive. Further, the program code can beencoded on a computer-readable storage media in a machine-readableformat, or on other non-transitory media or articles of manufacture. Thecomputer readable medium may include non-transitory computer readablemedium or memory, for example, such as computer-readable media thatstores data for short periods of time like register memory, processorcache and Random Access Memory (RAM). The computer readable medium mayalso include non-transitory media, such as secondary or persistent longterm storage, like read only memory (ROM), optical or magnetic disks,compact-disc read only memory (CD-ROM), for example. The computerreadable media may also be any other volatile or non-volatile storagesystems. The computer readable medium may be considered a tangiblecomputer readable storage medium, for example.

In some instances, components of the devices and/or systems describedherein may be configured to perform the functions such that thecomponents are actually configured and structured (with hardware and/orsoftware) to enable such performance. Example configurations theninclude one or more processors executing instructions to cause thesystem to perform the functions. Similarly, components of the devicesand/or systems may be configured so as to be arranged or adapted to,capable of, or suited for performing the functions, such as whenoperated in a specific manner.

The description of the different advantageous arrangements has beenpresented for purposes of illustration and description, and is notintended to be exhaustive or limited to the embodiments in the formdisclosed. Many modifications and variations will be apparent to thoseof ordinary skill in the art. Further, different advantageousembodiments may describe different advantages as compared to otheradvantageous embodiments. The embodiment or embodiments selected arechosen and described in order to explain the principles of theembodiments, the practical application, and to enable others of ordinaryskill in the art to understand the disclosure for various embodimentswith various modifications as are suited to the particular usecontemplated.

Within examples described above, the light control system 100 includes aUV light source, which emits UV light when activated. In additional oralternative examples, the light control system 100 can include a lightsource that can emit light in other frequency bands. For instance,within examples, the light control system 100 can include a light sourcethat can emit light, which can be used for purposes of disinfection,sanitization or killing germs, microbes, fungus, viruses, to a specifiedor non-specified target level.

More generally, the present disclosure provides for powering any lightsource (UV or non-UV) that requires high voltage power source to operatewithin a desired quality or requirement level in environments in which ahigh voltage power source is not available. For instance, as describedabove, the system can include the power buffer mechanism to overcome theshortage of high voltage power source.

Additionally, as described above, feedback and/or control mechanisms aredescribed to facilitate efficient operation of the power buffer, and/orfacilitate supplying sufficient power to the light source. The proposedfeedback and/or control mechanisms can also provide for operating thelight source within a desired range over time, under varying conditions,and/or when given varying parameters through time.

1. A light control system, comprising: a power converter configured toconvert an input power received from a power source to a supply power,wherein the power converter comprises a power factor corrector (PFC)configured to adjustably control an electrical parameter of the supplypower; a light source configured to, using the supply power, emit lightat an intensity related to the electrical parameter of the supply power;a sensor configured to sense a condition related to operation of thelight source; and a control device communicatively coupled to the PFCand the sensor, wherein the control device is configured to: receive,from the sensor, a sensor signal indicating an input parameter relatedto the condition sensed by the sensor, and based on sensor signal,provide a feedback signal to the PFC to cause the PFC to adjust, basedon the input parameter, the electrical parameter of the supply power. 2.The light control system of claim 1, wherein the light source is anultraviolet (UV) light source configured to emit UV light.
 3. The lightcontrol system of claim 2, wherein the light source is configured toemit the UV light at a wavelength within a far-UV spectrum.
 4. The lightcontrol system of claim 1, wherein the electrical parameter is at leastone of a voltage or a wattage of the supply power.
 5. The light controlsystem of claim 1, wherein the sensor is a light sensor configured tosense the light emitted by the light source, and wherein the inputparameter is related to at least one of an irradiance of the lightemitted by the light source, a voltage level of the light source, anefficacy level of the light source, an age of the light source, or anoperating frequency of the light source.
 6. The light control system ofclaim 5, wherein the sensor is a trigger sensor configured to sense anoccupancy of an environment in which the light source emits the light,and wherein the input parameter is related to the occupancy sensed bythe trigger sensor.
 7. The light control system of claim 1, wherein thesensor is a trigger sensor configured to sense an occupancy of anenvironment in which the light source emits the light, and wherein theinput parameter is related to the occupancy sensed by the triggersensor.
 8. The light control system of claim 1, wherein the PFCcomprises: a first PFC input configured to receive the input power fromthe power source; a second PFC input configured to receive a signal froma feedback circuit; and a PFC output configured to output a DC power,which is based on the input power at the first PFC input and the signalat the second PFC input, wherein the feedback circuit is coupled to thePFC output and the second PFC input, and wherein the signal provided bythe feedback circuit at the second PFC input is based on the inputparameter.
 9. The light control system of claim 8, wherein the feedbackcircuit comprises: a first operational amplifier (op-amp) including afirst inverting input, a first non-inverting input, and a first output,wherein the first output of the first op-amp is coupled to the secondPFC input, wherein the first inverting input of the first op-amp iscoupled to the PFC output; a second op-amp including a second invertinginput, a second non-inverting input, and a second output, wherein thesecond output of the second op-amp is coupled to the first non-invertinginput of the first op-amp, wherein the second inverting input of thesecond op-amp is coupled to a ground; and a logic circuit coupled to thesecond non-inverting input of the second op-amp, wherein the logiccircuit is configured to provide a reference voltage to the secondnon-inverting input of the second op-amp, wherein logic circuit isconfigured to select the reference voltage from among a plurality ofreference voltages based on the input parameter.
 10. The light controlsystem of claim 9, wherein the logic circuit comprises a variablevoltage divider having an output voltage, which is based on the inputparameter.
 11. The light control system of claim 8, wherein the powerconverter further comprises a pulse-width modulator (PWM) coupled to thePFC output of the PFC and communicatively coupled to the control device,wherein the PWM is configured to convert the DC power into analternating-current (AC) power, and wherein the control device isconfigured to provide the feedback signal to the PWM to cause the PWM toadjust, based on the input parameter, the electrical parameter of thesupply power.
 12. The light control system of claim 1, furthercomprising: a switch in communication with the control device, whereinthe sensor comprises a trigger sensor that is configured to detect anoverride condition, and wherein the control device is further configuredto, responsive to the trigger sensor detecting the override condition,actuate the switch to prevent the light source from receiving the supplypower.
 13. A light control system, comprising: a power convertercomprising: an input configured to receive an input power from a powersource during a time interval, a power buffer configured to store powerusing the input power received at the input during a first portion ofthe time interval, an output configured to output a supply power duringa second portion of the time interval, wherein the supply powercomprises a combination of power from (i) the input power received atthe input during the second portion of the time interval and (ii) thepower stored in the power buffer during the first portion of the timeinterval, a power factor corrector (PFC) between the input and theoutput, wherein the PFC is configured to adjust an electrical parameterof the supply power based on an input parameter; and a light sourceconfigured to, using the supply power during the second portion of thetime interval, emit light at a target intensity, wherein the input powerreceived during the second portion of the time interval is insufficientby itself for the light source to emit the light at the targetintensity.
 14. The light control system of claim 13, wherein the PFC isconfigured to receive the input parameter from the light source, andwherein the input parameter is related to at least one of an irradianceof the light emitted by the light source, a voltage level of the lightsource, an efficacy level of the light source, an age of the lightsource, or an operating frequency of the light source.
 15. The lightcontrol system of claim 13, wherein the PFC is configured to receive theinput parameter from the power buffer, and wherein the input parameteris indicative of an amount of the power stored in the power buffer. 16.The light control system of claim 13, wherein the PFC is configured toreceive the input parameter from a trigger sensor, and wherein the inputparameter is related to an occupancy of an environment in which thelight source emits the light.
 17. The light control system of claim 13,further comprising: a first trigger sensor configured to measure anamount of power stored in the power buffer; a second trigger sensorconfigured to sense an occupancy of an environment in which the lightsource emits the light; and a control device in communication with thefirst trigger sensor and the second trigger sensor, wherein the controldevice is configured to: responsive to a trigger-sensor signal receivedfrom the first trigger sensor, initiate a process to cause the lightsource to activate, and responsive to an override signal received fromthe second trigger sensor during the process, terminate the process foractivating the light source.
 18. The light control system of claim 17,wherein the first trigger sensor indicates that the amount of powerstored in the power buffer is greater than a threshold amount of power,and wherein the second trigger sensor indicates that the environment isoccupied.
 19. The light control system of claim 13, wherein the PFCcomprises an operational amplifier having a variable input as areference voltage.
 20. The light control system of claim 13, wherein thePFC comprises a variable voltage divider.
 21. A system for supplyingpower to a load, comprising: a power converter configured to convert aninput power received from a power source to a supply power, wherein thepower converter comprises one or more power control modules configuredto adjustably control an electrical parameter of the supply power; asensor configured to sense a condition related to operation of the load;and a control device communicatively coupled to the one or more powercontrol modules, wherein the control device is configured to: receive,from the sensor, a sensor signal indicating an input parameter relatedto the condition sensed by the sensor, and based on sensor signal,provide a feedback signal to the one or more power control modules tocause the one or more power control modules to adjust, based on theinput parameter, the electrical parameter of the supply power.
 22. Thesystem of claim 21, wherein the load is at least one of a light source,a motor, a travelling wave tube (TWT), a radar device, an electronicthruster, and a laser inferometer gauge.
 23. The system of claim 21,wherein the electrical parameter is at least one of a voltage or awattage of the supply power.
 24. The system of claim 21, wherein theelectrical parameter is at least one of a frequency or a pulse-width ofthe supply power.
 25. The system of claim 21, wherein the one or morepower control modules comprises a first power control module configuredto receive the input power and provide a first adjustable power as thesupply power at an output, wherein the first power control modulecomprises a first input configured to receive the input power from thepower source, a second input configured to receive a signal a feedbackmodule, and the output configured to output the supply power, whereinthe feedback module is coupled to the output and the second input, andwherein the feedback module is configured to provide the signal at thesecond input based on the input parameter.
 26. The system of claim 25,wherein the feedback module is integrated with the first power controlmodule.
 27. The system of claim 21, wherein the one or more powercontrol modules comprises a first power control module coupled to afirst feedback module and a second power control module coupled to asecond feedback module, wherein the first power control module isconfigured to provide, based on the input power and a first signal fromthe first feedback module, a first adjustable power to the second powercontrol module, wherein the second power control module is configured toprovide, based on the first adjustable power and a second signal fromthe second feedback module, a second adjustable power as the supplypower.
 28. The system of claim 27, wherein, to provide the feedbacksignal to the one or more power control modules, the control device isconfigured to: provide a first control signal to the first feedbackmodule, and provide a second control signal to the second feedbackmodule, wherein the first feedback module is configured to provide,based on the first control signal from the control device, the firstsignal to the first power control module to adjust the electricalparameter of the first adjustable power, and wherein the second feedbackmodule is configured to provide, based on the second control signal fromthe control device, the second signal to the second power control moduleto adjust the electrical parameter of the second adjustable power. 29.The system of claim 21, wherein the one or more power control modulescomprises a first power control module, a second power control module,and a third power control module, wherein the first power control moduleis configured receive the input power from the power source and output afirst adjustable power to the second power control module and the thirdpower control module, wherein the second power control module isconfigured to receive the first adjustable power from the first powercontrol module and output a second adjustable power to the third powercontrol module, and wherein the third power control module is configuredto receive the first adjustable power from the first power controlmodule and the second adjustable power from the second power controlmodule, and output a third adjustable power as the supply power.
 30. Thesystem of claim 29, wherein first power control module is coupled to afirst feedback module, wherein the first power control module isconfigured to provide, based on the input power and a first signal fromthe first feedback module, the first adjustable power to the secondpower control module, wherein, to provide the feedback signal to the oneor more power control modules, the control device is configured to:provide a first control signal to the first feedback module, provide asecond control signal to the second power control module, and provide athird control signal to the third power control module, wherein thefirst feedback module is configured to provide, based on the firstcontrol signal from the control device, the first signal to the firstpower control module to adjust the electrical parameter of the firstadjustable power, wherein the second power control module is configuredto provide the second adjustable power based on the first adjustablepower and the second control signal, and wherein the third power controlmodule is configured to provide the third adjustable power based on thefirst adjustable power, the second adjustable power, and the thirdcontrol signal.
 31. The system of claim 30, wherein the control deviceis configured to provide the first control signal at a first time, thesecond control signal at a second time, and the third control signal ata third time, and wherein the first time, the second time, and the thirdtime are different from each other.